Recently, a highly efficient power conversion apparatus utilizing the switching of a semiconductor device called power semiconductor chip for energy-saving purposes has been used in a wide variety of fields such as automobiles, railway equipment, industrial equipment and electric power equipment. Having a high heat value associated with energization, the power semiconductor chip used in this way needs cooling and is faced with demand for downsizing.
In a case where there are plural power semiconductor modules each equipped with a power semiconductor device and where each module is electrically connected with other components constituting a heat-dissipating body and a converter, the structure of the power conversion apparatus is complicated and enlarged in order to maintain cooling performance, electric performance and insulation performance.
A structure set forth in Patent Literature 1, for example, is cited as a prior art related to the invention.
A power conversion apparatus disclosed in Patent Literature 1 has a structure where plural circuit bodies carrying power semiconductor chips are mounted on a single heat-dissipating body. When the power semiconductor chips are mounted on the heat-dissipating body, stress is generated by using screws while a member for converting the stress to plane pressure and a member for eliminating clearance between the heat-dissipating body and the circuit body carrying the semiconductor devices are employed.